U.S. Pat. No. 8,521,352 discloses a device that performs an autonomous driving on a vehicle. This device changes a first autonomous driving mode to a second autonomous driving mode when data is not present in a target area on a map. In the second autonomous driving mode, the device provides an instruction of an option to switch an operation mode to a manual operation mode while maintaining a safer distance from another vehicle than a normal distance by, for example, reducing a speed of the vehicle.